Effects of pioglitazone on the expressions of p38 mitogen-activated protein kinase and transforming growth factor β-1 in cultured rat glomerular mesangial cells

Objective To observe the effects of pioglitazone on the expressions of p38 mitogen-activated protein kinase( p38MAPK) and transforming growth factor β-1( TGF-β1) in cultured rat glomerular mesangial cells( MCs) and explore its reno-protective mechanism. Methods MCs were cultured in the medium with normal glucose concentration( group NG),high glucose concentration( group HG),p38MAPK special inhibitor( group S) and pioglitazone( group P). The expression levels of phosphory1ated p38MAPK( p-p38) and total p38MAPK( t-p38) were measured by Western blot. The expressions of TGF-β1 mRNA were detected by semiquantitative RT-PCR. Results Compared with group NG,the p38MAPK activity and TGF-β1 mRNA expression increased significantly( P 0. 01) in group HG. Compared with group HG,p38MAPK special inhibitor inhibited markly HG-induced p38MAPK activity and TGF-β1 expression( P 0. 05). When treated with pioglitazone,p38MAPK activity and TGF-β1 expression decreased( P 0. 05),which were similar to group S. p38MAPK activity was positively correlated with TGF-β1 expression( r = 0. 587,P 0. 01). Conlusions Pioglitazone can suppress TGF-β1 expression of MCs via p38MAPK pathway,which may contribute partly to its reno-protection.